The Supreme King (Haō 覇王), is Jaden Yuki's evil side that took control over him while he was in the second alternate dimension looking for Jesse Anderson. Cold and ruthless, he serves as the antagonist of season three after the Dark World Army is defeated, starting from episode 136 until his defeat in episode 143. The King's goal is to rule the alternate dimension with an iron fist. According to Bastion Misawa (and later confirmed by Yubel herself), it was Yubel who orchestrated the possession of the King over Jaden.
The Supreme King is a shadowed figure dressed in black and gold medieval knight-esque armor with six tendril-like spikes, two jutting out of the armor's back and four jutting out of the shoulders, a headdress with a tall collar and a floor-length red cape. To signify his position as the Supreme King, he also wears a black helmet that functions as a crown. When he possesses Jaden, he dons his aforementioned outfit and Jaden's eyes become golden, giving him a somewhat demonic look. Jaden's face also elicits anger and hatred through a constant scowl, and his voice becomes coarsely layered (in the original version, he speaks in a bland monotone).
The Supreme King is first mentioned by Harpie's Brother, after the former was defeated by Jaden Yuki. Amazed by Jaden's courage and equity, Harpie's Brother begs Jaden to defeat the evil that rules his world (the Supreme King) and to become himself the King. As Jaden went deeper into the alternate dimension, more he couldn't control his emotions, especially anger and hatred, which resulted the awakening of his hidden powers. When Zure, Knight of Dark World killed a boy, who resembled Jesse Anderson, a glowing aura appeared around Jaden and Zure remarked that he isn't like the other duelists. When several Jaden's friends were sacrificed during the duel with Brron, Mad King of Dark World, Jaden let his hatred and anger to take control over him which awakened the Supreme King's powers inside himself. Jaden used that powers to win the duel, but his remaining friends were disappointed by his act and left him alone. After that duel the spirit of the Supreme King sensed Jaden's negative emotions and tempts him to evil with the "Super Polymerization" card that Brron previously tried to complete. He suggests that to truly defeat evil, Jaden himself must become evil. He successfully convinces Jaden, as thus far, being heroic had done nothing but get his friends killed. While in control, his first action is gathering his army to slaughter numerous duelists in order to complete the "Super Polymerization" card. He later begins to oppress many local villages, coercing their allegiance through strong-arm tactics and sets his eyes on a village that serves as his primary resistance for a trap for the survivors of his attacks. He can emit darkness powerful enough to generate strong wind. He also commands an army of ruthless minions capable of decimating entire villages; with his most prominent underlings are called the The Duelists of Death, which consist of Guardian Baou, Chaos Sorcerer, Skilled White Magician, Skilled Dark Magician, the former two actually Demise, King of Armageddon and Skull Knight. Ultimately, The Supreme King fails in his quest due to the efforts of Jim Crocodile Cook, Axel Brodie, Aster Phoenix, Zane Truesdale and indirectly, Syrus Truesdale. Although Jim's duel with The Supreme King leads to Jim losing his life, Axel was able to recover his eye. Later with the help of Aster and Zane, Axel invades The Supreme King's castle. He ties with The Supreme King in a duel and then uses the Eye of Orichalcum to free Jaden, at the cost of his own life. Zane then throws The Supreme King's helmet to the army in order to show them that their ruler has truly fallen and the army disperses soon after. The Supreme King would later come to haunt Jaden's past as a constant reminder of the atrocities he committed. In his duel against a Yubel-possessed Jesse Anderson, Jaden uses the "Super Polymerization" card which he used as the Supreme King, summoning "Rainbow Neos". However, Yubel plays "Last Trick" giving her possession of the "Super Polymerization" card. Bastion Misawa has previously told Jaden that The Supreme King is the dark half of Jaden's soul - however, he is not complete without him. Only by mastering the powers of The Supreme King without falling into inner darkness can Jaden truly become complete. Even Baou, former Supreme King's underling, stated they are the same person. Jaden mastered The Supreme King inside himself during the final Duel with Yubel. Jaden using the Supreme King's powers during the final battle against Yubel.During the final Duel with Yubel, the true nature of The Supreme King is exposed: The Supreme King was once a resident (prince in the dub) of an unnamed kingdom, destined to fight The Light of Destruction, and a close friend to a once-human Yubel. Because of how young he was at the time, Yubel offered to be transformed into a Duel Monster to protect him, an act that moved the King to the point of devoting himself to loving his only friend. His spirit would later be reincarnated and dormant within Jaden, until it was awakened by Yubel's actions. This realization gives Jaden the strength to forgive Yubel for what she's done, and to use "Super Polymerization" to fuse her within himself, reuniting Yubel and the King for all time. The flashback King looked almost exactly like Jaden (he just looked younger, he also lacked the demonic looking eyes he had when he has currently). It's stated that The Supreme King was later reborn as Jaden, but under the corruption of his own feelings of animosity and seriousness, prior to having to have lost his trust and his friends.As Jaden activated "Spiritual Fusion", the spirit of the King appeared once more, but he looked like Jaden in his current age. He tells her that the true enemy is The Light of Destruction, and that she will be freed from it and her soul will be fused with his. ===Season 4=== The Supreme King doesn't appear during Season 4, but he is shown in flashbacks during the end of Jaden's duel with Nightshroud. Jaden possesses both the King's and Yubel's powers. He gains golden eyes more than once, before they turn to Yubel's bi-chromatic style, and manifests power of generating wind during his second Duel with Sartorius. During this Duel, Jaden tells Sartorius that there is no power which can control destiny. But Sartorius counters by telling that he should know the allure of power more than anyone - having been controlled by The Supreme King. Jaden responds that such power no longer seduces him - and that power shouldn't be used to fulfilled your own desire. During the final Duel with Nightshroud, before her card was removed from play, Yubel reminded Jaden that he must believe in his own powers in order to win the Duel. Nightshroud tried to convince him that it's hopeless and he should surrender - he is alone, and no one else can fight. Jaden tells him he's wrong, stating that he's not the strong one. His soul was once drowned in darkness, and he hurt many of his friends - but that taught him something - to believe in the power of friendship and the strength of one's cards.
Although Jaden and The Supreme King are both played by the same voice actor (KENN in the Japanese version and Matthew Charles in the English version), their voices are much different. In the Japanese version, The Supreme King's voice is much deeper and foreboding in Jaden's subconscious while it is still Jaden's voice, but harsher and forceful on the outside though it is in a monotone. In the English version his voice is a harsher version of Jaden's voice complete with electronic effects; and while his voice does show emotion, it's never anything more than anger. The Supreme King is also quite taciturn and succinct, only talking when it is required or to spite his enemies The Supreme King is mostly calm and collected, but always carries an air of intimidation as noted by Axel Brodie. The Supreme King is also quite condescending, often mocking his opponent as he sees their efforts as futile because they are so weak in his eyes, although he doesn't deviate from his reserved attitude while doing so. As the Supreme King, his cruelty has no bounds as he is willing to sacrifice as many people as he has to in order to accomplish his goals along with his lack of remorse after defeating someone himself. However, he doesn't actively hunt for opponents; this was shown when he let Axel leave his castle without a chase after defeating Jim Crocodile Cook and he only dueled Jim because it was the latter that challenged him.
He plays an Evil Hero Deck, vile incarnations of Jaden's Elemental Heroes. Like Jaden, The Supreme King's tactics revolve around Fusion Summoning except he uses his own signature card, "Dark Fusion", a darker version of Jaden's traditional "Polymerization". "Dark Fusion" grants immunity to the Fusion Monster created by it from the opposition's Spell and Trap Cards during the turn it was summoned. The Supreme King also has access to the "Super Polymerization" card, which can use Fusion Material from both sides of the field and can't be negated by Spell and Trap Cards or the effects of Monster cards. Unlike Jaden, whose unconventional plays depend on chance, The Supreme King is straightforward and his arsenal uses a variety of effects that range from card destruction to immunity from opposing card effects that effectively reflect the supposed omnipotence of a monarch. The Supreme King possesses the Alternate Art version of Elemental Heroes "Avian", "Burstinatrix", "Sparkman" and an unreleased version of "Wildheart".